I have a continuous bipolar signal that can vary between ±1 mV and I would like to figure out the best way to measure it with high resolution without introducing a lot of noise.
My first thought is to amplify the signal with a instrument amplifier (looking at INA333) and digitize with a MCP3421 18-bit differential ADC. Using a gain of 8 and internal 2.048 V ref on the MCP3421, I believe the FSR is ±256 mV. I'd like to amplify my signal to use this FSR and get as much resolution as I can.
Is using an instrument amplifier the best way to go about this?
How can I use an instrument amp and maintain a bipolar output to feed to the ADC (do I use 2 opposed instrument amps?)
Is this possible to do without using a negative power supply for the reference? My board will be 0-5 V.
Any suggestions for the best way to do this are welcome (and greatly appreciated). I would love to see some schematics too if possible!